Lessons learned on air exchangers

Lessons learned on air exchangers:
1.The cold ductwork must be as short as possible. For every foot of duct, there is a large loss of heat from the dwelling. Using the insulated ducts that are currently available do not seem to help much.
2.Dampers need to be installed on the both sides of the exchanger, otherwise there is basically a hole to the outside of the building which will allow cold air into the building.
3.Any air exchanger must have actively balanced airflow in order for it to run at its optimum efficiency. If the flow isn't balanced, it again acts like a hole to the outside of the building.
4.It is important to install a quality external prefilter on both sides of the air exchanger and maintain them regularly.
5.To be continued....